Physical Sciences and Mathematics Commons^™

Results Of Webt, Vlba And Rxte Monitoring Of 3c 279 During 2006-2007, Niall Smith, Et. Al.

Blackrock Castle Observatory Publications

Context. The quasar 3C 279 is among the most extreme blazars in terms of luminosity and variability of flux at all wavebands. Its variations in flux and polarization are quite complex and therefore require intensive monitoring observations at multiple wavebands to characterise and interpret the observed changes.

Aims. In this paper, we present radio-to-optical data taken by the WEBT, supplemented by our VLBA and RXTE observations, of 3C 279. Our goal is to use this extensive database to draw inferences regarding the physics of the relativistic jet.

Methods. We assemble multifrequency light curves with data from 30 ground-based observatories and …

Variability Of The Blazar 4c 38.41 (B3 1633+382) From Ghz Frequencies To Gev Energies, Niall Smith, Et. Al.

Blackrock Castle Observatory Publications

Context. After years of modest optical activity, the quasar-type blazar 4C 38.41 (B3 1633+382) experienced a large outburst in 2011, which was detected throughout the entire electromagnetic spectrum, renewing interest in this source.

Aims. We present the results of low-energy multifrequency monitoring by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) consortium and collaborators, as well as those of spectropolarimetric/spectrophotometric monitoring at the Steward Observatory. We also analyse high-energy observations of the Swift and Fermi satellites. This combined study aims to provide insights into the source broad-band emission and variability properties.

Methods. We assemble …

B And I-Band Optical Micro-Variability Observations Of The Bl Lac Objects S5 2007+777 And 3c 371, Niall Smith, Et. Al.

Blackrock Castle Observatory Publications

We have observed S5 2007+777 and 3C 371 in the B and I bands for 13 and 8 nights, respectively, during various observing runs in 2001, 2002 and 2004. The observations resulted in almost evenly sampled light curves, h long. We do not detect any flares within the observed light curves, but we do observe small amplitude, significant variations, in both bands, on time scales of hours and days. The average variability amplitude on time scales of minutes/hours is ~2.5% and ~% in the case of S5 2007+777 and 3C 371, respectively. The average amplitudes increase to % and %, …

The Webt Campaign To Observe Ao 0235+16 In The 2003-2004 Observing Season - Results From Radio-To-Optical Monitoring And Xmm-Newton Observations, Niall Smith, Et. Al.

Blackrock Castle Observatory Publications

A multiwavelength campaign to observe the BL Lac object AO 0235+16 () was set up by the Whole Earth Blazar Telescope (WEBT) collaboration during the observing seasons 2003–2004 and 2004–2005, involving radio, near-IR and optical photometric monitoring, VLBA monitoring, optical spectral monitoring, and three pointings by the XMM-Newton satellite. Here we report on the results of the first season, which involved the participation of 24 optical and near-IR telescopes and 4 radio telescopes, as well as the first XMM-Newton pointing, which occurred on January 18–19, 2004. Unpublished data from previous epochs were also collected (from 5 optical-NIR and 3 radio …

Xmm-Newton Observations Of The Bl Lac Ms 0205.7+3509: A Dense, Low-Metallicity Absorber, Niall Smith, Et. Al.

Blackrock Castle Observatory Publications

The high-frequency-peaked BL Lac, MS 0205.7+3509 was observed twice with XMM-Newton. Both X-ray spectra are synchrotron-dominated, with mean 0.2–10 keV fluxes of and  erg cm^-2 s^-1. The X-ray spectra are well fit by a power-law with absorption above the Galactic value, however no absorption edges are detected, implying a low metallicity absorber () or an absorber with redshift above one (best-fit for an absorber with solar abundances). In either case the absorbing column density must be  cm^-2. A new optical spectrum is presented, with a absorption doublet detected at , but no other significant …